A main method for controlling plant diseases and nematodes is a method using chemical pesticides, and chemical pesticides have enabled stable production of crops to date. However, recently, it has become difficult to fully control the impact on the environment due to continuous use of chemical pesticides and emergence of drug-resistant bacteria by the conventional chemical pesticides; and diseases such as a bacterial disease which are difficult to control are developing into a major problem. Accordingly, biological control technology using a microorganism isolated from nature draws increasing attention and some of microorganism pesticides have been commercially-produced. However, the conventional microbiological pesticides have a defect that the effect is not stable and applicable diseases are fewer compared to chemical pesticides. In these circumstances, there has been growing demand for a novel microbiological pesticide which has new applicable diseases and exhibits a stable control effect.
As a plant disease control agent using a microorganism, a Talaromyces flavus agent, a Pseudomonas fluorescens agent, an avilurence Erwinia carotovora agent, a Trichoderma atroiviride agent, a Bacillus simplex agent, a Bacillus subtilis agent and the like are registered as a microbiological pesticide and have been used.
As a nematode control agent using a microorganism, a Pasteuria penetrans agent and a Monacrosporium phymatophagum agent are registered as a microbiological pesticide and have been used.
The specification of Japan Patent No. 2955655 (Patent Document 1) discloses a plant disease control agent using bacteria belonging to Bacillus amyloliquefaciens. The active ingredient of the plant disease control agent is the product of the microorganism and the bacteria per se are not used as a pesticide. Furthermore, the control target is a disease caused by filamentous bacteria and the document does not disclose the control of the bacterial disease. JP-A-2009-247302 publication (Patent Document 2) discloses a microorganism pesticide which can control the disease by filamentous bacteria and the bacterial disease at the same time in which viable bacteria cells per se are effective, but the document has no description on the nematode control.
The specification of Japan Patent No. 3471815 (Patent Document 3; WO 98/050422) discloses a plant disease control agent using Bacillus bacteria which can be used for a wide range of plant diseases and effective on corn rootworms, but the document has no description on the nematode control. The specification of Japan Patent No. 4071036 (Patent Document 4; US 2004/265292) discloses the Bacillus sp. D747 strain which can be used for controlling plant diseases and harmful insects, but the document has no description on the nematode control.
The specification of Japan Patent No. 3471811 (Patent Document 5; WO 96/032840) discloses a nematode control agent using Bacillus genus bacteria. The active ingredient of the nematode control agent is the bacteria or spore of the Bacillus firmus strain having an antinematode activity but the document has no description on the plant disease control. The specification of Japan Patent No. 4359653 (Patent Document 6; WO 1997/012980) discloses a method for controlling nematodes using a toxin produced by a novel Bacillus thuringiensis strain but the document has no description on the plant disease control.
In agriculture, chemical fertilizers are an important agricultural material which influences the yield of crops. However, 30 to 50% of the used chemical fertilizer components are not utilized in the crops but diffused in the environment, which causes eutrophication of rivers and groundwater contamination. A large quantity of fossil fuels is used in the production of chemical fertilizers and the production cost of the chemical fertilizers is increasing along with the soaring prices of fossil fuels. Furthermore, nitrogen oxide (NOx) as a decomposition product of a nitrogen fertilizer is said to be about 300 times more efficient in greenhouse emissions than carbon dioxide, and there is growing concern about global warming. Food shortage is expected in future due to the global population growth and therefore use of a material in order to increase the crop productivity is inevitable and there is growing need for a more environmentally-friendly material to replace the conventional chemical fertilizers.
In the light of such circumstances, studies have been made mainly on a broad range of Rhizobium bacteria, Pseudomonas bacteria and Bacillus bacteria. However, very few are in practical use because they are less effective.
As discussed above, no Bacillus bacterium which is effective on plant diseases in general, available in controlling nematodes and is effective in promoting plant growth has been known to date.